Such gas generators are intended for automobile safety.
One of the applications of such a generator is that of safety retention systems of the inflatable protective bag type, still called an “airbag”.
Certain types of gas generator, for example so-called hybrid gas generators and so-called “cold gas” generators include at least one reservoir of pressurized gas, the wall of which has a hole for letting through gas for filling the reservoir with pressurized gas, the hole being obturated by a plug welded to the wall.
Such generators are known, wherein the plug for example has a ball-shaped end coming into the hole.
A first drawback of these plugs is that their resistance welding generates significant burrs which are aggressive for the operator of the production line or for the bag which has to be inflated with the gas from the generator. Thus, the burrs form protruding and cutting rough patches outside the hole, which may undesirably tear the bag during its inflation, but which may also injure the persons handling the wall of the generator.
A second drawback of these plugs is that their shape forces them to be made by cold heading, which has a high manufacturing cost. Document FR-A-2 911 291 describes such a manufacturing method, in which a compact billet from metal wire and having initially a longitudinal fiber structure parallel to a generatrix is deformed by heading until a sphere is obtained, which is then itself deformed by heading until the desired shape is obtained, in which the fiber structure is oriented randomly.
Gas generators are also known, in which the gas reservoir is closed by a component which is both used for filling the reservoir and as a nozzle or diffuser for discharging the gas towards the bag in order to inflate it.
The drawback of these generators is that the part which has to be welded for obturating the hole is more expensive to make and the hole to be obturated is of a greater diameter which makes the filling and welding operation more complex.